Dissipation of heat from friction linings of clutch plates has long been a problem during operation of the clutch to engage or disengage the manual transmission from a vehicle engine. Fluid has been introduced within the clutch assembly to be forced between the friction linings and the pressure plate and flywheel as a solution to the problem, but this solution is complicated by the centrifugal force developed on the fluid while the clutch is rotating tending to sling the fluid radially outwardly of the plates. Even where the fluid has been successful in the cooling of the friction linings, a further problem of leakage of the cooling fluid from the clutch assembly is encountered because most wet clutches are adapted to the engine flywheel to make up the containment package. The present invention effectively solves the leakage problem in providing a truly self-contained wet clutch assembly.